Well, i wouldn't edit the config file but use "make menuconfig".
With that program you can easily find AMD/Intel related items.
For modules vs. builtin. I suggest compiling things directly in the kernel you ALWAYS use (graphics driver, file system, network, etc.) Because loading modules costs performance (also does a overloaded kernel
Well.. i guess it's the same like AMD vs. Intel, Gnome vs. KDE, etc.